上皮样血管平滑肌脂肪瘤临床病理观察

Clinicopathologic observations on epithelioid angioleiomyolipoma

目的观察上皮样血管平滑肌脂肪瘤(epithelioid angiom yolipoma,EAML)的病理特征、免疫表型,探讨其组织起源。方法对1例肝脏、2例肾脏EAML的临床表现、病理组织学形态、免疫表型进行观察并复习文献。结果镜下见肿瘤主要由成熟脂肪细胞、上皮样细胞组成,并见薄壁血管及泡沫细胞;上皮样细胞呈散在或片状分布在脂肪组织间,细胞体积大,胞制质透亮,核大居中,呈圆形或卵圆形,无异型及核分裂象,间质内见少量淋巴细胞;免疫组化:上皮样细胞vimentin、S-100、HMB-45阳性,Desmin、SMA灶性阳性,EMA阴性,Ki-67阴性。结论 EAML是一种十分少见且具有恶性潜能的间叶源性肿瘤,易被误诊为恶性肿瘤,免疫组化对其鉴别诊断有重要意义。

Objective To investigate the clinicopathologic characteristics,immunophenotype and histogenesis of epithelioid angioleiomyolipoma { EAML}. Methods We observed 3 cases of EAML in liver and kidney and reviewed the literature. The clinical manifestation, morphological appearance and immunophenotype were analyzed in the tumor. Results Histological examination demonstrated the tumor was composed of mature adipose cells and epithelioid cells. Thin parietal vessel and foam cells were observed. Epithelial-like cells were scattered or of lamellar distribution in adipose tissues. The cells were large in size ,with translucent cytoplasm and large nuclear in center, seemed round or oval, without atypia and mitotic activity. A small amount of lymphocytes were observed in interstitial substance. Immunohistochemical examination showed the epithelioid cells were positive in vimentin,S-100 and HMB-45,partly positive in desmin and SMA and negative in EMA and Ki-67. Conclusion EAML is a kind of rare and potential malignant tumor. It is easy to be confused with malignant. Immunohistochemistry is of great significance in the differential diagnosis of EAML.